Phase I trial of HIV-1 subunit vaccine (gp 160, Microgenesys), is under way at the NIAID. The laboratory of DNA Virus Research is following these vaccinees in terms of CMV isolation from different body fluids (saliva, blood, urine). Cultures of CMV are performed before and following vaccinations at regular time intervals. A second trial of this vaccine enrolled HIV-1 positive asymptomatic patients. It is hoped that stabilization of CD4 cell numbers in these patients will result in reduced incidence of sytemic CMV. A third trial has recently begun, using the Microgenesys subunit p24 vaccine to immunize HIV-1 seropositive asymptomatic patients.